xcode - iOS - MKMapView - Draggable Annotations

Question

I have the annotation ready to go, but trying to figure out on how to make it draggable with my code:

-(IBAction) updateLocation:(id)sender{

    MKCoordinateRegion newRegion;

    newRegion.center.latitude = mapView.userLocation.location.coordinate.latitude;
    newRegion.center.longitude = mapView.userLocation.location.coordinate.longitude;

    newRegion.span.latitudeDelta = 0.0004f;
    newRegion.span.longitudeDelta = 0.0004f;

    [mapView setRegion: newRegion animated: YES];


    CLLocationCoordinate2D coordinate;
    coordinate.latitude = mapView.userLocation.location.coordinate.latitude;
    coordinate.longitude = mapView.userLocation.location.coordinate.longitude;

    MKPointAnnotation *annotation = [[MKPointAnnotation alloc] init];

    [annotation setCoordinate: coordinate];
    [annotation setTitle: @"Your Car is parked here"];
    [annotation setSubtitle: @"Come here for pepsi"];


    [mapView addAnnotation: annotation];
    [mapView setZoomEnabled: YES];
    [mapView setScrollEnabled: YES];
}

Thanks in advance!

Answer 1

To make an annotation draggable, set the annotation view's draggable property to YES.

This is normally done in the viewForAnnotation delegate method.

For example:

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
    if ([annotation isKindOfClass:[MKUserLocation class]])
        return nil;

    static NSString *reuseId = @"pin";
    MKPinAnnotationView *pav = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:reuseId];
    if (pav == nil)
    {
        pav = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:reuseId];
        pav.draggable = YES;
        pav.canShowCallout = YES;
    }
    else
    {
        pav.annotation = annotation;
    }

    return pav;
}

If you need to handle when the user stops dragging and drops the annotation, see:
how to manage drag and drop for MKAnnotationView on IOS?

In addition, your annotation object (the one that implements MKAnnotation) should have a settable coordinate property. You are using the MKPointAnnotation class which does implement setCoordinate so that part's already taken care of.